The first principle is that you must not fool yourself -- and you are the easiest person to fool.

What I cannot create, I do not understand.

To teach superstitions as truth is a most terrible thing.

-- Hypatia

Fables should be taught as fables, myths as myths, and miracles as poetic fancies.

-- Hypatia

Once in one's life, everything should be called into doubt.

-- René Descartes

A great many people think they are thinking when they are merely rearranging their prejudices.

-- William James

I much prefer the sharpest criticism of a single intelligent man to the thoughtless approval of the masses.

-- Johannes Kepler

The important thing is not to stop questioning. Curiosity has its own reason for existing.

-- Albert Einstein